NEHRP Clearinghouse
- Title
- Investigation of Local Geology Effects on Strong Earthquake Ground Motions.
- File
- PB84161488.pdf
- Author(s)
- Huang, M.
- Source
- National Science Foundation, Washington, DC., January 1984, 256 p.
- Identifying Number(s)
- EERL-83-03
- Abstract
- Accelerograms recorded at four stations in the Pasadena area during the 1971 San Fernando, the 1970 Lytle Creek, the 1968 Borrego Mountain and the 1952 Kern County earthquakes are analyzed to investigate local geology effects on strong earthquake ground motions. Spatial variations of the ground motions at two nearby stations are also investigated. A two-dimensional model considering inclined propagating P and S waves in a horizontal-layered structure is studied. It is found that the transfer function between the free surface motions and the bedrock outcrop motions to multiple incident waves having different amplitudes, angles and arrival times is quite different from that for a single incident wave. It is concluded from these studies that the effects of the source mechanism and the seismic wave travel paths upon the site ground motion can be comparable to the effect of the local geology.
- Keywords
- Orientation; Geology; Depth; California; Sites; Seismic waves; Mathematical models; Secondary waves; Pasadena (California); Seismological stations; Primary waves; Stresses; Theses; Motion; Rocks; Earthquakes; Geological faults